Apparatus for cooling cement clinkers



H. HABEL APPARATUS FOR COOLING CEMENT CLINKERS June 23, 19 59 6Sheets-Sheet 1 Filed July 5, 1957 INVENTOR flex; A25 8 June 23, 1959 VH. HABEL 2,891,321

APPARATUS FORYCOOLING CEMENT CLINKERS Filed July 5, 1957 6 Sheets-Sheet2 June 23, 1959 H. HABEL 2,891,321

APPARATUS FOR COOLING CEMENTCLINKERS Filed July 5. 1957 6 Sheets-Sheet aINVENTOR //e/az A4966! H. HABEL APPARATUS FOR COOLING CEMENT CLINKEIRSJune 23, 1959 6 Sheets-Sheet 4 Filed July 5, 19 57 INVENTOR A e/az #06e/ June 23, 1959 H. HABEL 2,891,321 APPARATUS FOR COOLING CEMENT cuuxsasFiled-July 5. 1957 e Sheets-Sheet 5 June 23, 1959 H. HABEL APPARATUS FORCOOLING CEMENT CLINKERS 6 Sheets-Sheet 6 Fi led July 5. 1957 j I r LiiNlrl i rP. \w m INVENTOR A eg'az 5 46 e/ United States Patent 2,891,321APPARATUS FOR COOLING CENIENT CLINKERS Heinz Habel, Erfurt, Germany,assignor to VEB Zementanlagenbau Dessau, Dessau, Germany This inventionrelates to burnt or calcined material, such as for example cementclinker, obtained in kilns or the like; and more particularly to amethod and apparatus for cooling such material.

While the invention will be described in relation to cement clinker, itshould be understood that the method and apparatus ofthis invention areapplicable to the cooling of other burnt, calcined or fused materialswhich are also in grain form.

For the purpose of cooling cement clinker, cooling drums and inclinedgrate or horizontal coolers have hitherto been employed. With a view tosuccessfully carrying out the cooling of the clinker, the following fiverequirements should be achieved, 'which requirements are either notachieved at all or only partially afiorded by known cooling devices. l

. These requirements are the following: i

. (1) The cooler should be uniformly charged with hot clinker materialin order to obtain a uniform layer thickness.

(2) The amount of clinker falling through the grates should be reducedas much as possible so as to eliminate the necessity for providingconveying arrangements for clinker removal below the grates. Further,such reduction in the amount of clinker material falling through thegrates reduces wear on the elements arranged below the grates and thusprotects such elements, whereby work stoppages are reduced andproduction is consequently increased. i Q

(3) Efiicient distribution and conducting of the cooling air as Well aseflicient contact of the air with the clinker material should beprovided.

(4) Deflecting and conducting away of the combustion air, with respectto the quantity and temperature of such combustion air, should beefiiciently carried out for the purpose of obtaininga uniform hightemperature.

(5) Deflection of a quantity of air of a temperature suitable to dry thefuel which is required for the burning or firing should be achieved.

It is an object of this invention to provide a method and apparatus forcooling clinker material which fulfills all of the aforementionedrequirements.

The cooling apparatus to the invention comprises a rotary grate. Therotary grate may comprise a plurality of horizontally-rotatable,superimposed annular ring-like members provided with grate plates orsegments. The several rings may be rotated separately at differentspeeds or they may be stationarily arranged. The several rings should bemounted eccentrically relative to each other.

A confining or enclosing wall is arranged outside the outermost ring,which wall is spirally-shaped. The hot clinker material is supplied tothe rotary grate cooler at that area of the cooler which corresponds tothe junction of the largest and smallest radius of the spiral.

The speed of revolution of the outermost ring is adjusted in accordance.with the output of the rotary kiln. Due to the spiral shape of theenclosing wall, the clinker, upon rotation of the outermost ring, isurged toward the center of the cooler. This feeding movement of theclinker takes place slowly and uniformly throughout the cooler.

The grate plates or segments to which the clinker falls may be fittedwith horizontally-extending nozzles, or the grate covering element maybe provided with horizontally-directed slots. In this manner, thefalling of the clinker material through the grate elements is prevented.The grate elements or plates are arranged in a step-wise manner, andeach ring is arranged eccentrically to the one thereabove. All of thegrate rings may be of the same construction. With the exception of theinnermost ring, all of the rings should be adjustable with regard totheir speed of revolution. The innermost ring is also eccentricallyarranged relative to the preceding ring, but being however stationarilymounted and surrounding a vertical delivery duct. The delivery ductterminates at its lower end in a rotatable disc arranged at somedistance from the lower end of the duct proper. Upon rotation of thisdisc the clinker which has collected on the disc is deflected or scrapedoff of the disc by a scraping device. Theamount of clinker to be scrapedfrom the disc may be adjusted by altering the number of disc revolutionsor by adjusting the position of the scraping device. The amount ofclinker to be removed is adjusted in such a manner that the entry ofundesired air through the delivery duct is prevented.

It is advantageous to effect a separation of the heated air to an.extent determined by its temperature, so that at any time, not only thequantities of the air, but also the temperatures can be controlled andthus adjusted. The separation of the hot air quantities is efiected insuch a manner that the relatively large amounts of air of lowertemperature which are required for the complete cooling of the clinkercannot by themselves mix with the cooling air of higher temperature.

Other objects and advantages of the invention will be apparent from thefollowing description when taken in connection with the accompanyingdrawings forming a part of this-specification, and in which:

Fig. 1 is a vertical section, shown somewhat schematically, of a rotarykiln operatively associated with a first embodiment of a rotary gratecooler made in accordance withthe invention, the figure at the same timeschematically indicating the cooling process;

Fig. 2 is a perspective view of the inclined chute of Fig. 1 along whichthe burnt material falls into the grate cooler;

Fig. 3 is a top plan view of cooler shown in Fig. 1;

Fig. 4 is anenlarged section through a portion of the cooler grating andshowing the detail thereof;

Fig. 5 is a perspective view of the grating plates of Fig. 4;

Fig. 6 is a section taken along lines 6-6 of Fig. 1;

Figs. 7, 8 and 9 show details of the driving arrangement for therotation of the grate rings;

Fig. 10 is a schematic representation of the grate rings without thegrating surfaces and the driving arrangement;

Fig. 11 is a vertical section through a second embodiment of a rotarygrate cooler made in accordance with the invention and comprising asecond cooling stage for obtaining a high cooling effect;

Fig. 12 is a vertical section through a third embodiment of a rotarygrate cooler made in accordance with the inthe grating surface of thevention, which cooler includes a step-shaped grating ar-.

Fig. 1, reference numeral 1 indicates a rotary kiln which i is operatedby a coal dust firing, as schematically indicated by reference numeral2.. The burnt material 3 falls along an inclined chute 4 into the rotarygrate cooler. The chute 4 is provided with nozzle-like openings 5 forthe --passage of air as perspectively shown in Fig. 2. Cooling airintroduced through the nozzles 5 contacts and consequently precools thehot clinker material during its travel along the chute 4. Thiscoolingair, furthermore cools the chute proper, thus prolonging the lifethereof. a

l The cooling air is supplied to the nozzles through an air duct 11a(Figs. 1 and 2) by means of a connecting line 11b. A throttle valve 110is built into the line 11b foradjustin'g the air flow. The coolersurface onto which the clinker material 3 falls, and by which the latteris supported, comprises annular members or grate rings 7, 8 and 9arranged eceentrically relative to each other, as shown in Fig. 3. Therings 7, 8 and 9 form jointly with the clinker material thereon a hollowcone. The ring 7 is arranged below a spiral-shaped confining Wall 10,which Wallis provided with cooling air nozzles ll which in turncommunicate with the air duct 11a. The spiral shape of the wall causes areduction of the inner diameter of the cooling space cross section ascompared to a circular cross section. Upon rotation of ring 7, whichrotates beneath the wall 10, the clinker material-due to the decrease ofthe cross section of wall 10-is positively pushedonto the grate ring 8.The beginning of the spiral (largest diameter) and the end of the spiral(smallest diameter) may either be directly connected with each other theshortest way as shown by the dash-dotted line in Fig. 3, or thetransition may be eifected gradually. Due to rotation of the grate rings7, 8, and 9, the clinker material 3 is continuously conveyed toward thecenter of the cooling arrangement. Below the ring 9 extends a shaft 12which terminates at its bottom end in a rotatable disc 13. For thepurpose of permitting the pas sage of air through the shaft 12, thelatter is provided with openings 14. The cooled clinker material 3 isdirected by a stripper '15 to a receiving funnel 16, through which thecooled clinker material 3 falls onto a conveying arrangement 17 fortransportation away from the plant. The rotatable disc 13 may, forexample, be drivenby a bevel gear drive indicated at 13a. The number ofrevolutions of the disc 13 may be adjustable, or the position of thestripper 15 may be made variable, whereby the amount of clinker materialto be fed to the funnel 16 can be adjusted.

'The'a'ir escaping from the spaces or zones 19 and 20 may be recoveredand used for any desired purpose, or may be conducted to the chimney.

The quantities of air which have to be supplied to the cooler throughthe nozzle 5, 11 and '14, and the slots or passages of the grate ring,(to be presently described), are produced by blowers or the like. Thelines through which-this air 'is conducted to the various inlets havebeen shown in Fig. l.

A cylindrical separating wall '28, extending between the air spaces orzones '18 and 20 and 19 and 20, respectively, extends downwardly to thesurface of the clinker material 3. In this manner, travel of the coolingair above the clinker layer from one zone to the other, is prevented. Anair-cooled ring 29 forms the lower end portion of this wall 28'. Thecooling air is conducted from this ring 29'through nozzles 2911 into thezone 20. The required cooling air is branched off from the same duct211a from which air flows to and through the nozzles 11. The connectingline is'formed by pipes 11d into which throttle valves 11c are built inorder to control the air flow. With a view to controlling thetemperatures of the cooling air from the zones 18 and 19, these zonescommunicate with the zone 20 through connecting channels. Thecross-sectional area of these channels are adjustable by regulatingflaps, as for example, indicated at 30.

Fig. 3 is a top plan view of the grating surface of a rotary gratecooler, for example, the cooler shown in Fig. 1, the various elementsbuilt into the cooling space, however, being omitted and the figurebeing a horizontal section through the air duct 11a and the nozzles 11.The grate rings can be recognized at 7, 8 and 9, while the cooling airnozzles 11 are schematically shown as being arranged in thespiral-shaped confining wall 10 which is provided above the outermostring 7. Further, this fig ure makes it clear thatthe grate rings arecovered by segments or plate-s serving as grate elements.

A cross sectional view of these segments or plates is presented in Fig.4. A perspective view further illustrating the plates is given in Fig;5. In order to prevent the clinker material from falling through thegrate elements, which may cause the soiling and increased wear of theelements and the supports arranged below the grate elements, the coolingair outlets 22 are provided only on the vertical walls of the grateplates 21. Each grate plate 21 includes a top plate 21a supported byspaced ribs 21b. Between the supporting ribs 2112 are formed airpassages, the path of the cooling air being indicated by the arrows inFigs. 4 and 5. A part of the lower extremities of ribs 2117 are joinedby a cross plate 21e. Each grate plate 21 is sealed against the platesof the adjacent ring by a movable sealing piece 23. The grate plates 21are detachably and thus interchangeably secured to circular carriers 24.

The plates 21 are secured against displacement transverse to thecircular carriers 24 by the cooling ribs provided'with abutment pieces21d. In order to interchange the plates, the latter arelifted to anextent corresponding to the height of the abutments -by pulling towardsthe center of the cooler. The mounting of new plates is effected inreverse manner. The circular carriers 24 may be driven, for example, bygear rims 25. The carriers 24 ride on rollers 26 which bear on rollertracks 27. The rollers 26 are arranged equally spaced along the track27. The rollers are slightly conical in shape and are held in properalignment by a spacing .ring (not shown), as is common practice in ballor roller bearings.

The gear rims 25 are preferably driven by means of driving pawls. Figs.7, 8 and 9 illustrate a preferred embodiment of such a pawl drivingarrangement. By means of a reciprocating connecting or push rod 40parallelly mounted drive shafts 42 are made to rotate in oscillatingmanner through a lever and rod system 41a, 41b and 410. The shafts 42are mounted in bearings 43 and move in opposite directions. The drivingpawl levers 44 are rigidly connected with the shafts 42, while the pawls45 proper are rockably mounted on the levers 44. The pawls are loaded bysprings in order to assure engagement with the teeth of the gear rims25. In the operative position the pawls 45 bear with their ribs. 46against counter rib 47 of the pawl levers 44. The end position of thepawls 45 is thus fixed.

Fig. 10 showsseparately the position of the driving elements (pawllevers and pawls) for eachgrate ring. As shown in this figure, each ringis separately driven. In order not to crowd the drawing the rings havebeen shown without their grating surfaces while only fragments of thecircular carriers 24 have been illustrated. The rocking movements of theconnecting or push rods 40 are advantageously produced by hydraulic ormechanical driving mechanisms'known per so which are adjustable insteplessmanner. For this reason these driving mechanisms have notbeenshown.

Fig. ,6, showing a cross-section through the cooling device above thegrating elements, illustrates the hot air zones 18, 19 and 20. V

Fig. 11 is a schematic illustration of a different embodiment of arotary grate cooler made in accordance with the invention. The upperportion of the cooler is identical with the cooler described in theprevious embodiment, so that. no further description thereof will Thesame reference numerals as in the first have been employed for likeparts. However, the rotatable disc 13 of the embodiment shown in Fig. 1,has been replaced by an additional lower rotary grating unit 31 which,regarded from thedirection' of feed of the clinker, constitutes areversal of the upper grating arrangement. That is to say, the clinkerdoes not fall into the hollow of a stepped hollow cone; but rather fallsonto the outer surface of a downwardly stepped cone formed by theseveral grate rings; The center of this lower grating arrangement ischarged with clinker material through the duct 12. Due to rotation ofthe grate rings of the arrangement 31, the clinker is outwardlyconducted away from the center. The clinker is scraped from the marginalportion of the lowermost ring of the unit 31 by a stripper element 15soas to be dropped upon the conveyor 17. However, it is also possible toconduct the clinker by overflow from anypoint on this lowermost ring tothe conveyor 17, for example, by arranging a'chute' or the like belowthe grating unit 31. As in the upper grating unit, cooling airisintroduced through nozzles 01" the likeinto the clinker mass passingover the lower grating unit 31.

In order to keep the quantities of employed cooling air withinreasonable limits, the cooling air entering at 35 passes through gratingunit 31 as shown by the arrows 36, and is then drawn into a blower 38 inthe direction of the arrow 37. From the blower 38, the air is blown inthe direction of arrow 39 under gratings 7, 8 and 9, from whence itfollows the path shown in the first embodiment of Fig. 1. The coolingair introduced through nozzles and 11 is, however, produced in aseparate blower.

Fig. 12 illustrates a further embodiment of rotary grate cooler. In thisembodiment only the outer ring 7 is employed and the clinker material ispushed from all sides into a funnel-shaped hollow cone. The side wallsof this hollow cone are made up of plates 32 which are arranged in aninclined manner. These plates form in conjunction with each otherslot-shaped openings for the passage of cooling air. The angle of thecone wall is designed to correspond to the natural angle of thematerial, i.e., the clinker, being loosely deposited on the grating. Inthis embodiment, replacement of the grate plates can be made in aparticularly easy manner. Further, there are present less elements whichare subject to wear, all of the elements are constructed in aparticularly simple manner, and work stoppages due to repairs arepractically avoided.

For the purpose of obtaining a better cooling effect, a hollow cylinder34 is built into the duct 12. This cylinder 34 has deflecting platessimilar to those of duct 12, and it may be stationarily arranged or maybe corotatably connected to the rotatable disc 13. For the purpose ofproviding an even more effective cooling, the cylinder may be chargedwithin air as illustrated in Fig. 12. In doing so, the air enters thecylinder 34 from the space 48 through the clinker layer in the duct 12.The air is supplied to the space 48 as in the other embodiments.

A still further modification of a rotary grate cooler is shown in Fig.13.

In this embodiment a hollow cylinder 34 is arranged directly beneath theouter grate ring 7. The radii of the confining walls of the cylinder arerelatively large. As compared with the embodiment of Fig. 12, no hollowcone is provided. The embodiment of Fig. 13 permits the construction ofgrate coolers having the same base surface. The height of the cylinder34 is altered dependent on the cooling effect which is required. Thiscylinder comprises a large cooling area accommodated within the smallestpossible space. The cooling area is constituted by very simple elements.The clinker material falls downwardly by gravity between the outer andinner wall elements of the cylinder 34. The cooling necessary.embodiment airentersthe clinker from space 49 through the elements ofthe outer cylinder wall, while the air escapes through the elements ofthe inner cylinder wall into space 20. As in the other embodiments theair is supplied through blowers. This modification operatessubstantially as the previously described constructions.

The grate structure of the invention, due to its cooling effect on thecement clinker, exhibits an important and beneficial influence on thequality of the cement. Further, the production costs of the cement areconsiderably reduced, since considerably less fuel is. consumed. At thesame time the area and the manufacturing costs of thecooler proper arereduced.

The rotary grate cooler of the invention is suitable for all materialswhich are to be heated by a firing or burning process and which are tobe cooled by atmospheric air. A further important advantage of thecooler resides in the fact that the cooling can be etfeeted within avery small space, to such an extent that the cooled clinker may beconveyed on rubber conveying belts or the like without causing heatdamage thereto.

I have described preferred embodiments of my invention, but it isunderstood that this disclosure is for the purpose of illustration only,and that various omissions and changes in shape, construction,proportion and arrangement of parts, as well as the substitution ofequivalent elements for the arrangement shown and described, may be madewithout departing from the spirit and scope of the invention as recitedin the appended claims.

What is claimed is:

1. Apparatus for cooling calcined cement clinker and like grainymaterials, said apparatus comprising a spiral shaped confining coolerwall, means for feeding material to be cooled along said cooler wall, aplurality of rotatable ring-like members arranged below said coolerwall, said ring-like members being arranged eccentrically relative toeach other, means for separately rotating said ring-like members atvarying speeds and in dillerent directions of rotation to convey thematerial to be cooled to the center of the cooler apparatus, and meansfor continuously introducing cooling air through the confining wall andthrough said ring-like members.

2. Apparatus for cooling cement clinker according to claim 1, in whichsaid ring-like members are covered with grating elements, having meansto prevent the clinker material from falling through the walls thereof,and said ring-like members with their grates being staggered in such amanner that they are capable to support the clinker falling thereon in amanner of a hollow cone, the total inclination of said conecorresponding to the natural angle of the material supplied to thecooler.

3. Apparatus for cooling cement clinker according to claim 1, in which apair of vertically-arranged cylinders forming an annular passage for thematerial to be cooled, are positioned outwardly of the outermostring-like member, said cylinders having inclined, interchangeable,stepped grating elements, the air-introducing means including means forblowing cooling air between said grating elements into the mass ofmaterial to be cooled.

4. Apparatus for cooling cement clinker according to claim 1, whereinsaid means for feeding material comprises an inclined chute throughwhich the material to be cooled is fed to the cooler, said chute havingnozzlelike slots for admission of cooling air therethrough.

5. Apparatus for cooling cement clinker according to claim 1, in whichthe ring-like members are covered by interchangeable, segment-shapedplates having depcnding cooling ribs, the air-introducing meanssupplying a flow of cooling air between the cooling ribs, said plateshaving depending vertical walls facing the center of the cooler, saidvertical walls having nozzle-like slots positioned to permit the coolingair to flow through the material to be'cooled.

6. Apparatus for cooling cement clinker according to claim 1, in whichthe cooler has a vertical delivery duct positioned within and depending.fromthe innermost ring-like membengthe bottomof said duct opening abovea rotatable disc, .the disc being sized and'spaced below the lower edgeof the duct a sufiicient distance to permit a piling of the material .tobe cooled thereon without trickling of the material oil .the edge of thedisc, and an adjustable stripper arranged .to strip the material fromthe disc upon rotation of the latter.

7. Apparatus for cooling cement clinker according to claim 6 in whichthe rotatable disc is formed of a plurality of eccentrically-rnountedgrate rings, each comprising a plurality of segment-shaped plates, andadjustable means for driving said rings at varying rotational speedsrelative to each other, the rings forming a downwardlystepped cone, theangle of inclination of said cone corresponding to the natural angle ofthe material to be cooled.

8. Apparatus for cooling cement according to claim lfi,

in which a cooling space is provided above said ;;grate rings and acylindricalseparating wall divides said cooling space into coolingzones, said separating Wall having an air-cooled lower edge portionpositioned to contact the upper surface of the material to be cooled,and cute 8. le shawl s i d h s oo in zo s to nduct away the cooling airtherein.

:9. Apparatus for vcooling cement clinker according to claim-.8, inwhich the separating wall .is ,provided with openings connecting thecooling zones and-adjustable References Cit ed inthefile of this patentUNITED STATES PATENTS 1,558,11? Sherban' Oct. 20, 1925 1,718,243Lindhard June 25, 1929 1,989,662 I Bernhard et 211-. Feb. 5, 19352,153,112. Windecker .Apr. 4, 1939 2,641,064 Foner June 9, 1953Zimmermann Feb. 16, 1954'

